Fountain pen ink containers are normally configured in such a way that an essentially bellied or bulbous base section passes at the top into a narrower collar section provided with an external thread. A sealing cap can be screwed onto the collar section which, on the inside, accommodates a sealing disk which, when the screw cap is put on, is pressed in a fluid-tight fashion against the front surface of the collar section.
Apart from reposing glass containers provided with an ink withdrawal opening at the side, standing containers of plastic materials are also known. However, on account of their dimensions, such containers are not carried with them by students since they cannot be accommodated in students' cases and problems might arise when the same are carried in the school satchels, more particularly when glass containers are involved. To this is added the circumstance that a student does not require for his or her daily needs such large quantities of writing fluid (ink) as are made available by these containers.
Even though lately more and more writing implements or fountain pens equipped with ink cartridges have gained acceptance, it has nevertheless to be recorded that particularly fountain pens of high quality are for the most part constructed in the form of so-called piston-type fountain pens, i.e. they possess, in their interior, an as a rule cylindrical fluid chamber which is refillable with the aid of a piston that is actuated from the outside. This chamber may either be integrated into the fountain pen casing or be constituted by a piston cartridge, a so-called converter, which is inserted into the fountain pen in the form of a unit which has to be handled separately. In both cases, the refilling of the ink chamber is effected in that the piston is moved up to the frontmost stop so that the internal volume of the ink reservoir container restricted by the piston assumes a minimum value. A connection with the environment is established via the nib or via the front aperture of the refillable cartridge. For refilling, the nib or the front end of the piston cartridge is immersed into the ink bottle or submerged in the same so that, by the return movement of the piston, writing fluid or ink is drawn in and the ink reservoir container is filled.
Apart from the fact that this refilling operation in piston-type fountain pens is somewhat more time-consuming anyhow due to the separate handling of the ink bottle than is the case in cartridge-type fountain pens, there arises the further problem that, when refilling the ink, one generally soils at least one's hands. For, when piston-type fountain pens are refilled, the latter always have to be dipped into the ink as far as over the lower rim of the gripping portion so that the external surface of the fountain pen is often wetted by the ink far into the gripping depressions and contaminated by this. Blue or black ink can be perceived only with difficulty on the external fountain pen surfaces which frequently are finished in dark tones so that the fountain pen has to be thoroughly washed and dried before it is used again.
A further problem arises owing to the circumstance that, in piston-type fountain pens, care has to be taken when refilling that the entire nib is surrounded with ink. This results in that inkpots or ink bottles can be emptied only with difficulty. Because, once the ink level has sunk to such an extent that, when the nib is immersed, the latter does no longer lie in its entirety with a submersion dimension of approximately 1 mm below the level of the writing fluid, the fountain pen draws in "air" when being filled. With this it is impossible for the ink storage chamber in the fountain pen to be filled completely with ink so that the refilling operation has to be carried out at increasingly shorter intervals. Over and above that, the air trapped in the ink reservoir, when the fountain pen is subjected to thermal action, such as e.g. when the fountain pen is held in the hand over extended periods or when the same is exposed to solar radiation, has a negative effect in that the increasing air volume urges excessive ink from the nib.
Also in fountain pens provided with refillable cartridges it is not possible to eliminate the problems described in the foregoing, especially since, in this case, the probability of soiling one's hands is greater due to the circumstance that the cartridge, when being immersed, can only be stabilized by supporting one's fingers on the upper rim of the ink bottle neck.
It is true that it has been attempted to lessen the problem stated in the foregoing by imparting a special design to the inkpots or ink bottles so that, besides the actual main chamber, separeted by a partition, a secondary chamber is created. Thereby the ink bottle does receive a highly complex shape which renders the manufacturability more difficult and augments the costs of the ink bottle.
The invention is based upon the technical problem of providing, more particularly for students, a small and handy spare bottle for writing fluid which can be carried without any problem inter alia also in students' cases, comprising contents sufficing for approximately two to three or even more piston-type fountain pen fillings and provided with an attachment, with the aid of which one succeeds in emptying the spare bottle completely with the exception of an insignificant residual quantity and, at the same time, to facilitate the handling of the spare bottle on the one hand and of the fountain pen or the refillable cartridge on the other in such a way that the risk of soiling oneself with ink during the refilling operation is effectively checked. It is intended furthermore to increase the tightness of the spare bottle in the state in which it is closed by a cap portion or a screw cap as well as in the docked state to a writing implement and to provide a configuration with which also the filling of writing implements not provided with a suction piston having an ink reservoir and an ink conducting system as well as of ink cartridges disposed in the writing implement is possible.